Pursuant to IPC, the invention refers to processing of plastics, namely to formation or interconnecting and subsequent treatment of formed products, and quite exactly to connecting each product by means of a thermally shrinkable film. Moreover, the invention may also refer to multi-layered packaging containing artificial resins, in particular polyester. Still further, the invention may also refer to physics, namely to testing and in particular to constructional concept of indicators.
In this, the purpose of the invention is to create an indicator for proving of tightness of a packaging consisting of at least partially light permeable thermoplastic film, wherein such indicator should enable occasional i.e. periodical testing by means of a penetration dye, by which each user and each environment should be prevented from any risks of pollution by said penetration dye.
A method of detecting tightness of weakness of welded packaging is generally disclosed in WO 2005/159500 A1 or in CN 101726395 B.
The invention generally refers to a packaging, namely to testing of said packaging, and in particular to proving tightness of seals in a sterilization or any other packaging, which is produced either in industrial processes, or in the sterilization area by means of specific welding appliances.
Quite exactly, the invention refers to proving quality of seals in a soft sterilization packaging, which is usually made of a layer, which is permeable for each sterilization media and represents sterilization paper or any other filtering layer, as well as of a non-permeable translucent synthetic layer, usually a PET/PP or PET/PE laminated film. When such packaging is closed, both layers are welded along the edges by means of special welding apparatus and by means of temperature and pressure, by which a closed sterilization packaging is produced, which is permeable for sterilization media and provides a barrier for microorganisms.
Such welding appliances are capable to realize at least 6 mm wide seal between said laminated film and said barrier layer, wherein due to various reasons from time to time such seal is not continuous and tight. This means that such seal contains non-welded areas in the form of channels, which extend between said non-welded layers towards the exterior and enable microorganisms to intrude towards each sterilized content.
The invention is dealing with proving of tightness and quality of seals in such packaging. The object of the invention is to create a test, namely an indicator for proving tightness of sterilization, which should comply with the standard ISO EN 11607 and ASTM F 1929, to which ISO EN 11607 refers, and which would also be user friendly and would enable daily routine control.
Pursuant to said standard ASTM F 1929, tightness of seals is tested by means of colored dye like the fluid TRITON X-100, which is characterized by extremely efficient intruding into pores, so that each irregularity in the seal becomes visible as soon as the dye has penetrated into it.
The method of such testing is however not quite user friendly, since the liquid must be introduced drop by drop into each packaging, which means that the packaging must be open i.e. not welded on at least one end portion thereof, which may lead to pollution of the surrounding with said testing liquid. Due to its penetration efficiency, removing of liquid is then extremely difficult, which leads to huge problem in various tests, since in most cases pollution occurs despite to due care.
Commercially available state of the art sets like e.g. HAWO INK TEST (www.hawo.com) include said testing liquid, which is then introduced, preferably drop by drop, into each examined packaging. Such test is characterized by set in kit comprising 75 ml of testing liquid and twenty pipettes, which are suitable for introducing of testing liquid into each examined packaging. There is always a high risk of pollution of the surrounding, since said testing liquid must be drop by drop introduced into open flexible packaging, which is held by one hand, by simultaneously observing penetration of said testing liquid. All known providers offer the same principle of testing.
The invention solves this problem by means of a container, in which the testing liquid is stored and which is then inserted and welded into each packaging, upon which said container is broken within the closed packaging, so that the testing liquid is released within the packaging, which is then followed by visual observing i.e. evaluation of quality of seals in accordance with ASTM F 1929.
Container can be provided in various embodiments like a rigid one or a flexible, or in any other acceptable form, however, it must enable releasing of testing liquid by means of breaking or in any other way within the closed packaging. A rigid container is e.g. a capsule made of a rigid disintegratable material, which is due to a mechanical loading broken, by which the testing penetration liquid is released.
A flexible container is furnished with regular seals, which form two chambers, which are separated by means of a narrowed passage i.e. meander, which makes extraction of testing liquid easier, since upon inserting the indicator into each examined packaging in vertical position the testing liquid is transposed from the first chamber into the second chamber adjacent to a weakened seal, upon which said narrowed passage is pressed and interrupted, by which the required hydrostatic pressure is easily established in order to discontinue said weakened seal and extract the testing liquid.
Testing by using such approach requires inserting such container into each examined packaging, which is followed by closing i.e. welding of packaging and then also with releasing of the testing fluid by means of breaking the container.
The same container and the same procedure of releasing the testing liquid can also be used for introducing said liquid into reusable sterilization packaging, wherein the liquid assures maintaining surgical instrument in wet conditions and prevented from drying each waste thereon prior to cleaning.
When said liquid is introduced into a reusable packaging, then a slightly greater container is required as an independent unit, which can be inserted into said reusable packaging in order to release the liquid, or said container can also be conceived as a part of said reusable sterilization packaging.
Method for introduction of said testing penetration liquid for the purpose of identification of irregularities of seals of a sterilization or any other packaging, or for introduction of penetration liquid into a reusable sterilization packaging, comprises releasing of the liquid from a rigid or flexible or any other container by means of disintegration thereof upon being inserted into each examined packaging, which can be closed.
The container for introduction of said testing penetration liquid for the purposes of identification of irregularities in seals of each sterilization or any other packaging is characterized by releasing of testing liquid on the basis of disintegration of a weakened seal in a flexible container, or of any other seal or any other part of the container, which is achieved by exposing each packaging, together with the indicator inserted therein, to each required pressure.
The previously described container for testing liquid is further characterized by seals, the regular seals of which form two chambers for storage of testing liquid, which are separated by means of a narrowed passage, which makes extraction of testing liquid easier, since upon inserting the indicator into each examined packaging in vertical position the testing liquid is transposed from the first chamber into the second chamber adjacent to a weakened seal, upon which said narrowed passage is pressed and interrupted, by which the required hydrostatic pressure is easily established in order to discontinue said weakened seal and extract the testing liquid.
The invention proposes an indicator for proving tightness of seals in a packaging consisting of at least partially light permeable thermoplastic film, wherein such indicator is conceived as a cushion consisting of two liquid-impermeable flexible film layers, which are welded to each other along the complete circumference and between which a penetration liquid is stored, and wherein said layers are welded to each other in such manner that two chambers are formed between them, which are connected with each other in the area of a narrowed passage and with the possibility of transposition of said penetration fluid between each other, and wherein at least one section of the seal between said film layers is weakened.
In a preferred embodiment of the invention, said first chamber is located on the first end portion of the indicator, the second chamber is located on the second end portion of the indicator, and said weakened section of the seal is arranged on the terminal area of the second chamber, which is located on the second end portion of the indicator and faced away from the first chamber.
The previously mentioned embodiment is furthermore characterized in that said seal between the layers comprises, in addition to said weakened section, at least two longitudinal sections, which are spaced apart from each other, as well as at least one transversal section, while said narrowed passage between both chambers is formed by means of two meanders, which are deflected towards each other and arranged at least approximately in the central region of said longitudinal sections of the seal.
The preferred embodiment of the invention further provides that said weakened section of the seal is trapezoidal and comprises a central transversal section and two lateral sections, which extend to the firstly mentioned section towards the second chamber and converge in a direction towards the first chamber.
The invention moreover preferably provides that the circumference of the indicator is arrow-shaped and adapted due to visualization of a direction of extraction of the penetration liquid from the first chamber into the second chamber towards the weakened section of the seal. Within the said context, the circumference of the indicator can be formed by two longitudinal edges, which extend at least approximately parallel to each other, the first transversal section, which is arranged on the first end portion and is deflected towards the first chamber, and the second transversal section, which is arranged on the second end portion and is deflected in a direction away from the second chamber.